#288DD9
Closest named color: Dark Sky Blue (#448EE4). oklch(62.4% 0.145 246.5), rgb(40, 141, 217).
Aa
Black text reads best on this color (5.90:1).
About this color
#288DD9 is a medium-light, vivid blue. In OKLCH its lightness is 62%, its chroma 0.145 and its hue 246°. Its hue sits on the cool side of the wheel. The nearest named color is Dark Sky Blue (#448EE4), ΔE 0.026 away. Black text reads best on it, at 5.90:1.
| Hue family | Blues |
| Lightness | medium-light (62%) |
| Chroma | vivid (0.145) |
| Temperature | cool |
| Nearest name | Dark Sky Blue (#448EE4) |
| Black text | 5.90:1 |
| White text | 3.55:1 |
Values
| HEX | #288DD9 |
| RGB | rgb(40, 141, 217) |
| HSL | hsl(206, 70%, 50%) |
| OKLCH | oklch(62.4% 0.145 246.5) |
Contrast
WCAG 2 contrast ratios are the conformance target: AA needs 4.5:1 for body text and 3:1 for large text, AAA needs 7:1. APCA Lc values are supplementary guidance from the WCAG 3 drafts.
| Pair | WCAG 2 | Result | APCA | APCA guidance |
|---|---|---|---|---|
| White text on #288DD9 | 3.55:1 | AA large text | Lc -68.2 | Content text, not long reading |
| Black text on #288DD9 | 5.90:1 | AA | Lc 41.4 | Non-text elements, placeholder text |
| #288DD9 text on white | 3.55:1 | AA large text | Lc 62.7 | Content text, not long reading |
| #288DD9 text on black | 5.90:1 | AA | Lc -39.0 | Non-text elements, placeholder text |
Tints and shades
A 50–950 scale built in OKLCH: the hue is held, lightness follows a Tailwind v4-like curve, and every step is kept inside the sRGB gamut. This color sits at step 500.
-
Step 50
50
#F0F6FC
oklch(97% 0.01 247.9)
-
Step 100
100
#DFECF7
oklch(93.7% 0.02 243.4)
-
Step 200
200
#C5DCF2
oklch(88.4% 0.039 247.1)
-
Step 300
300
#9BC6EC
oklch(80.9% 0.071 245.5)
-
Step 400
400
#61A7E3
oklch(70.7% 0.113 246.2)
-
Step 500
500 (this color)
#288DD9
oklch(62.4% 0.145 246.5)
-
Step 600
600
#0078C2
oklch(55.6% 0.145 246.5)
-
Step 700
700
#0065A4
oklch(49.2% 0.127 246.3)
-
Step 800
800
#005287
oklch(42.6% 0.111 246.5)
-
Step 900
900
#054470
oklch(37.6% 0.095 246.7)
-
Step 950
950
#082842
oklch(26.9% 0.061 247.3)
#288DD9 with color blindness
Simulated with the Machado et al. (2009) model. ΔE is how far the color moves: below about 0.02 you would not notice a change.
| Vision | Seen as | Shift (ΔE) |
|---|---|---|
| Protanopia (no red cones) | #6990DC | 0.056 |
| Deuteranopia (no green cones) | #4F81D8 | 0.039 |
| Tritanopia (no blue cones) | #009FA9 | 0.102 |
| Achromatopsia (no color) | #888888 | 0.145 |
Harmonies
Hue rotations in OKLCH that keep this color's lightness and chroma.
Complementary
The opposite hue (180°).
- #288DD9
#288DD9
oklch(62.4% 0.145 246.5)
- #BE7400
#BE7400
oklch(62.5% 0.138 66.8)
Analogous
Neighbouring hues, 30° either side.
Split complementary
The two hues beside the complement (150° and 210°).
Triadic
Three hues spaced 120° apart.
Palettes with this color
Curated palettes that contain a color within ΔE 0.04 (OKLab) of #288DD9, closest first.
Similar named colors
The eight closest entries in our named color list, with their ΔE distance.
- Dark Sky Blue #448EE4 ΔE 0.026
- Water Blue #0E87CC ΔE 0.027
- Chefchaouen Blue #4895EF ΔE 0.045
- Cool Blue #4984B8 ΔE 0.052
- Dodger Blue #1E90FF ΔE 0.056
- Soft Blue #6488EA ΔE 0.058
- Steel Blue #4682B4 ΔE 0.058
- Blue NCS #118AB2 ΔE 0.062
Use #288DD9 in your product
Turn it into light and dark UI roles checked for contrast, then export to Tailwind v4, shadcn/ui, CSS or design tokens.